candela or lumens

[centaur21]

I am looking at some lighting in Cooper-Crouse Hinds catalog and have a question about a conversion factor.

The catalog gives an example of a type of light and if you use a different watt lamp, it gives a conversion factor. Am I to multiply the conversion factor to the number of lumens or to the candelas found for the given lamp example?

For example, the catalog example uses a 175W Mercury Vapor 8600 lumen lamp. The candelas for this lamp is 1443. If I am using a mercury-halide lamp instead, the conversion factor is 1.63. Now am I to multiply this conversion factor by the lumens or candelas? I am very new to lighting and learning as I go.

Thanks for the help!

 

[rbulsara]

Refer to this:

http://www.electro-optical.com/whitepapers/candela.htm

Better yet refer to IES reference book.

candela and lumens are related but not interchangeable. They are two diffrent quantities.

For lighting level calcaulations all you need to know is lumens from a light fixture, normally.

 

[centaur21]

I don't have an IES book. I was just wondering about the conversion factor that crouse-hinds has listed in their catalog. It is not clear, and as said before I am new to lighting, as to what the ocnversion factor corresponds to.

 

[IRstuff]

Is there some misunderstanding of the lumen outputs listed in their documentation?

http://www.crouse-hinds.com/crousehinds/resources/Lighting Selection Guide - Step 4.pdf

Seems pretty clear to me.

TTFN

 

[centaur21]

Let me clear this up. In the catalog, there are actual numbers that are listed as CONVERSION FACTORS if you are not using the given example. Maybe I am misreading it, but I think I am supposed to use the conversion factor, 1.63 which is what they list in the catalog for a 175W mercury halide lamp. The lamp they are using in the candela curve chart is a mercury vapor lamp, therefore they give specific numbers to use to convert from mercury vapor to mercury halide. The conversion factor listed is different depending on the mercury halide lamp wattage.

So my original question was, this specific conversion factor, 1.63, am I multiplying it by the original lumens listed in the mercury vapor lamp or the candelas found from the chart of the mercury vapor lamp?

 

[centaur21]

See page 9 of 12 at the following link to see an example of what I mean. See on the right upper corner where it reads LAMP WATTS and CONVERSION FACTOR.

http://www.crouse-hinds.com/crouseh...search='crousehinds series conversion factor'

 

[IRstuff]

And if you had bothered to read page 4 of the link I posted, you would been able to figure this out yourself.

TTFN

 

[rbulsara]

centaur21:

Did you read the note in the box where the conversion factors are given, that you are referring to on page 4? Where does it say it is for cadela to lumens? Nor there is any coversion factor of 1.63. Those factors are to adjust for wattage of the incandecent lamps, as the table is for 300W.